2 * Copyright (C) 2014 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
22 #include "private/libc_logging.h"
24 static const char* syslog_log_tag = NULL;
25 static int syslog_priority_mask = 0xff;
28 syslog_log_tag = NULL;
31 void openlog(const char* log_tag, int /*options*/, int /*facility*/) {
32 syslog_log_tag = log_tag;
35 int setlogmask(int new_mask) {
36 int old_mask = syslog_priority_mask;
37 // 0 is used to query the current mask.
39 syslog_priority_mask = new_mask;
44 void syslog(int priority, const char* fmt, ...) {
47 vsyslog(priority, fmt, args);
51 void vsyslog(int priority, const char* fmt, va_list args) {
52 int caller_errno = errno;
54 // Check whether we're supposed to be logging messages of this priority.
55 if ((syslog_priority_mask & LOG_MASK(LOG_PRI(priority))) == 0) {
59 // What's our log tag?
60 const char* log_tag = syslog_log_tag;
61 if (log_tag == NULL) {
62 log_tag = getprogname();
65 // What's our Android log priority?
66 priority &= LOG_PRIMASK;
67 int android_log_priority;
68 if (priority <= LOG_ERR) {
69 android_log_priority = ANDROID_LOG_ERROR;
70 } else if (priority == LOG_WARNING) {
71 android_log_priority = ANDROID_LOG_WARN;
72 } else if (priority <= LOG_INFO) {
73 android_log_priority = ANDROID_LOG_INFO;
75 android_log_priority = ANDROID_LOG_DEBUG;
78 // glibc's printf family support %m directly, but our BSD-based one doesn't.
79 // If the format string seems to contain "%m", rewrite it.
80 const char* log_fmt = fmt;
81 if (strstr(fmt, "%m") != NULL) {
82 size_t dst_len = 1024;
83 char* dst = reinterpret_cast<char*>(malloc(dst_len));
86 const char* src = fmt;
87 for (; dst_len > 0 && *src != '\0'; ++src) {
88 if (*src == '%' && *(src + 1) == 'm') {
90 size_t n = strlcpy(dst, strerror(caller_errno), dst_len);
97 } else if (*src == '%' && *(src + 1) == '%') {
98 // We need to copy pairs of '%'s so the %m test works.
102 *dst++ = '%'; --dst_len;
103 *dst++ = '%'; --dst_len;
106 *dst++ = *src; --dst_len;
112 // We can't let __libc_format_log do the formatting because it doesn't support
113 // all the printf functionality.
115 vsnprintf(log_line, sizeof(log_line), log_fmt, args);
117 if (log_fmt != fmt) {
118 free(const_cast<char*>(log_fmt));
121 __libc_format_log(android_log_priority, log_tag, "%s", log_line);